Light Projection Target Mire For Curvature Measurements

Abstract

The present invention refers to the light ring target mire ( 8 ) used for accurate measuring of the radii of curvature of spherical and non spherical reflective surfaces, with a fixation target for the patient, holes that allow the observation by the slit lamp ( 7 ), holes to be illuminated ( 4 ), using an illumination system composed by a header which has an exit lens from the illumination system, focused filament, an intermediary circle and a light stop with an useful area for the target mire, being alternatively projected with arc shaped rings, or passing through rings in a precise circumlinear shape, allowing to be used with different types of illumination systems, providing measurements of any reflective surface, not being limited to ocular exams.

1 ) “LIGHT PROJECTION TARGET MIRE FOR ACCURATE MEASUREMENTS OF THE RADII OF CURVATURE OF SPHERICAL AND NON SPHERICAL REFLECTING SURFACES”, characterized by a device, light ring target, used for precise measurements of the radii of curvature or reflective surfaces of any shape, having 72 holes, more than or less than, for light projection and two additional holes that allow the observation through the eyepieces of the slit lamp or any other ocular microscope or any other device to which the target may be attached, externally illuminated by a light or any other type of illumination, in particular, for the slit lamp that has an illumination system composed by header which has a light bulb, an exit lens from the illumination system, focused filament, an intermediary circle and a light stop with an useful area for the target mire, being alternatively projected with arc shaped rings, or passing through rings in a precise circumlinear shape, allowing to be used with different types of illumination systems, providing measurements of any reflective surface, not being limited to ocular exams. 
   
   
       2 ) “LIGHT PROJECTION TARGET MIRE FOR ACCURATE MEASUREMENTS OF THE RADII OF CURVATURE OF SPHERICAL AND NON SPHERICAL REFLECTING SURFACES” according to  claim 1 , is characterized by the way that the holes are illuminated by the focused light rays that are at precise pre-determined angles for their reflection and homogeneously illuminate the said holes and also project at the reflective surface the circular target mire, with homogeneous illumination and accurate dimension. 
   
   
       3 ) “LIGHT PROJECTION TARGET MIRE FOR ACCURATE MEASUREMENTS OF THE RADII OF CURVATURE OF SPHERICAL AND NON SPHERICAL SURFACES” according to  claim 1 , is characterized by holes (or passing through arcs or rings) positioned circularly that allow to create a projection mire of many light ring targets composed by illuminated light spots (or continuous rings, or arcs) which allow to determine the curvature radii of the reflective surface, in this case, the cornea. 
   
   
       4 ) “LIGHT PROJECTION TARGET MIRE FOR ACCURATE MEASUREMENTS OF THE RADII OF CURVATURE OF SPHERICAL AND NON SPHERICAL REFLECTING SURFACES”, according to  claim 1 , is characterized by two conical surfaces, having accurately determined angles, designed for providing uniform reflection of the light, in order to reflect the greatest amount of light, providing the desired illuminated diameter of the target, considering the focusing of the light from the illumination system of the slit lamp and thus its angulation, which is relevant to reflect the light to the desired direction and may be designed to work within any other focused and projected light source, with the intention of deviating the light circularly for obtaining the homogeneous and total illumination of the target mire. 
   
   
       5 ) “LIGHT PROJECTION TARGET MIRE FOR ACCURATE MEASUREMENTS OF THE RADII OF CURVATURE OF SPHERICAL AND NON SPHERICAL REFLECTING SURFACES”, according to  claims 1 ,  2 ,  3 ,  4  and  5 , is characterized by the geometric calculus considering the rays coming from the intermediary circle, that reach the central parts of the reflective surfaces in order to reflect the light rays that come from the useful parts on surfaces  2  and  3  (reflection angle is the same as the incidence angle-reflection law) and to reach surface  4  at reflective angle α at surface  2 , and at reflective angle β on surface  3 , by the reflection law, will be reflected at the same incidence angle and defining distance “d” and the image size 2h between the incidence points  2  and  3 , angles α, β and σ are obtained by the equations (1), (2), (3), (4), (5) and (6): 
     
       
         
           
             
               
                 
                   α 
                   = 
                   
                     
                       90 
                       + 
                       δ 
                       - 
                       
                         arc 
                          
                         
                             
                         
                          
                         tg 
                          
                         
                           d 
                           h 
                         
                       
                     
                     2 
                   
                 
               
               
                 
                   ( 
                   3 
                   ) 
                 
               
             
             
               
                 
                   β 
                   = 
                   
                     
                       270 
                       - 
                       ϕ 
                       - 
                       
                         arc 
                          
                         
                             
                         
                          
                         tg 
                          
                         
                           d 
                           h 
                         
                       
                     
                     2 
                   
                 
               
               
                 
                   ( 
                   4 
                   ) 
                 
               
             
             
               
                 
                   φ 
                   = 
                   
                     α 
                     - 
                     δ 
                   
                 
               
               
                 
                   ( 
                   5 
                   ) 
                 
               
             
             
               
                 
                   σ 
                   = 
                   
                     90 
                     - 
                     β 
                     - 
                     
                       arc 
                        
                       
                           
                       
                        
                       tg 
                        
                       
                         d 
                         h 
                       
                     
                   
                 
               
               
                 
                   ( 
                   6 
                   )